CSE 5522: Survey of Artificial Intelligence II: Advanced Techniques

Instructor: Alan RitterTA: Fan Yang

Logistics

• Instructor: Alan Ritter– Email: ritter.1492@osu.edu– Office: Dreese 595– Office Hours: Thursdays 3:30-4:30pm

• TA: Fan Yang– yang.549@buckeyemail.osu.edu– Office: Bolz Hall 113– Office hours: Wednesday 1-2pm

• Course website:– http://aritter.github.io/courses/5522.html

• Homework Submission & Discussion Forums:– https://carmen.osu.edu/

Evaluation

• Homework assignments (30%)• In-Class midterm (20%)• In-Class final (20%)• Course Project (30%)– Proposal (10%)– Code + Data (10%)– Final Report (10%)

Homework

• Written questions• Programming exercises– Implement some algorithms discussed in class– Please use one of the following languages: C++, Java,

C#, Matlab, Python– If you want to use another language, ask the instructor

and TA first.– Make your code easy to run and write a README

• OK to discuss with others in class. – Please write up your own answers / code.

Project

• Team up in groups of 2-3 students• Fairly open-ended• Apply some of the methods we discuss in class

to applications• Examples:– http://cs229.stanford.edu/projects2011.html

Project (cont)

• Proposal (Due March 12)– 2 pages– What is the problem you are trying to solve?– What method are you proposing to use?– What data will you use?– What is the baseline?

• Final Report (Due May 30)– 4 pages

Textbooks

• A number of relevant books on website– You may want these books eventually anyway…

• The Russell and Norvig book is the one traditionally used for the class– But doesn’t cover all topics

• I will write lecture notes and slides• Should be able to get through the class

without purchasing any books.

Q: what is probability?

• Probability: Calculus for dealing with nondeterminism and uncertainty

• Probabilistic model: Can be queried to say how likely we expect different outcomes to occur.

Why Should Computer Scientists Care about Probability?

• Programs should have predictable behavior!– Everything should be deterministic?

• Randomness is something to be avoided?– Race conditions in parallel program– If your program produces unpredictable output

there must be a bug!• Symbolic AI (GOFAI)– Logic, Search– Examples: Chess, Circuit Design, Expert Systems

Why Should Computer Scientists Care about Probability?

• Logic is not enough• The world is full of uncertainty and

nondeterminism• Computers need to be able to handle this• Probability: new foundation for CS

What is statistics?

• Statistics 1: Summarizing data– Mean, standard deviation, hypothesis testing,

etc…• Statistics 2: Inferring probabilistic models

from data– Structure– Parameters

What’s in it for Computer Scientists?

• Statistics and CS are both about data• Lots of data lying around these days• Statistics lets us summarize and understand it• Statistics lets data do our work for us

Stats 101 vs. This Class

• Stats 101 is (sort of) a prerequisite for this class• Stats 101 deals with one or two variables– We will deal with thousands or millions

• Stats 101 focuses on continuous variables– We will focus on discrete ones (mostly)

• Stats 101 ignores structure• We focus on computational aspects• We focus on CS applications

Applications of Probability and Statistics in CS

• Machine Learning and Data Mining• Automated reasoning and Planning• Computer vision and graphics• Robotics• Natural language processing and speech• Information Retrieval• Databases / Data management

More Applications

• Computer networks and systems• Ubiquitous computing• Human computer interaction• Computational biology• Computational neuroscience• Your application here

Goals for the class

• We will learn to:– Put probability distributions on everything– Learn them from data– Do inference with them

Topics

• Basics of probability and statistical estimation• Mixture models and the EM algorithm• Hidden Markov Models and Kalman Filters• Bayesian Networks and Markov Networks• Exact Inference and Approximate Inference